AuthorTopic: USB commands (TR203) (Read 4821 times)

I am using TR-203, and would like to make java application to communicate with device and setting it. My app can read info from GPS - get the current position and other data. I created writer, to send commands to device (command + checksum), added serialport event listener. But i dont get any response, only data about position and so on. Can someone tell me how to get response from command that i sent? Thank you